1. Technical Field
The present invention relates to a distributed sensing system; and more particularly, to a distributed seismic sensing system for sensing seismic disturbances and other phenomenon.
2. Description of the Prior Art
Seismic sensing systems are known in the art. For example, U.S. Pat. No. 5,623,455), issued to Norris.
One disadvantage of Norris's seismic data acquiring system is that the recording units RU and data acquisition units DAU use batteries which are expensive and time consuming to replace, and the recording units RU and data acquisition units DAU are also heavy devices that are not easily handled during deployment.
Moreover, the use of a fiber having fiber Bragg Gratings in combination with a piezoelectric transducer is shown and described in U.S. Pat. No. 5,675,674, issued to Weis, entitled "Optical Fiber Modulation and Demodulation System," hereby incorporated by reference. See also U.S. patent application Ser. No. 08/933,544, filed Sep. 19, 1997, U.S. Pat. No. 5,986,749 hereby incorporated by reference, which shows and describes a fiber optic sensing system for an oil logging production system having a sensor element with an optical fiber and fiber Bragg Gratings, a piezoelectric transducer, a photo detector, and electroplates.